[Retros] Games determined by their first and last moves

[Francois Labelle]

As promised, below are new problems in 5.0 moves, and solutions to 
problems in <= 4.5 moves, but first...

---------------------------------------------------

STRONGER VERSIONS OF PROBLEMS IN <= 4.5 MOVES

I noticed that I can omit the identity of the capturing piece in two of 
the ?x?# problems, so the problems

 > 1. e3/e4 ... 3. QxP# (same solution as P0008139)
 > 1. h3 ... 4... QxR# (new?)

can be improved to

1. e3/e4 ... 3. mate by capturing a pawn
1. h3 ... 4... mate by capturing a rook

---------------------------------------------------

NEW PROBLEMS IN 5.0 MOVES

As before, I exclude problems that do not need their first move to be 
specified, and problems that are really 4.5 moves long with the colors 
flipped and a useless first move added.

Strong problems (no destination square given):
1. c4 ... 5... mate by promoting to bishop
1. e3 ... 5... mate by promoting to bishop
1. e4 ... 5... mate by promoting to bishop (similar to above)
1. d3 ... 5... RxR#

Normal problems:
1. Nf3 ... 5... Qe7#
1. d3/d4 ... 5... Qe8#
1. e3/e4 ... 5... Kf8#
1. f3/f4 ... 5... Kf6# (P1000378)
1. e3 ... 5... Nxg4#
1. f4 ... 5... Rf5# (similar to P1013044 which is better)
1. g4 ... 5... Bd5#
1. g4 ... 5... Bh3#

Weaker problems (type of checkmate is specified):
1. Nf3 ... 5... Bf5## (double checkmate)
1. f3 ... 5... Nf7.# (discovery checkmate)

I'll post the solutions in 1 week.

---------------------------------------------------

SOLUTIONS TO PROBLEMS IN <= 4.5 MOVES

 > 1. a3 ... 5. mate with a rook
1. a3 e5 2. Nc3 Bxa3 3. Ne4 Bf8 4. Ra5 Ke7 5. Rxe5#

 > problems of the type ?x?#:
 > 1. e3/e4 ... 3. mate by capturing a pawn
1. e3 e5 2. Qh5 Ke7 3. Qxe5#
1. e4 e5 2. Qh5 Ke7 3. Qxe5#
 > 1. h3 ... 4... mate by capturing a rook
1. h3 d5 2. f3 Bxh3 3. Rxh3 Qd6 4. Rg3 Qxg3#
 > 1. h4 ... 5. RxP# (solution similar to "1. a3 ... 5. mate with a rook")
1. h4 e5 2. Nc3 Qxh4 3. Ne4 Qd8 4. Rh5 Ke7 5. Rxe5#

 > in 3.5 moves:
 > 1. Nf3/Nh3/h4 ... 4. Bg5#
1. Nf3 e6 2. d4 Ke7 3. Qd3 Kf6 4. Bg5#
1. Nh3 e6 2. d4 Ke7 3. Qd3 Kf6 4. Bg5#
1. h4 e6 2. d4 Ke7 3. Qd3 Kf6 4. Bg5#
 > 1. Nf3/f3/g4 ... 4. Qe5#
1. Nf3 e5 2. d4 exd4 3. Qxd4 Ke7 4. Qe5#
1. f3 e5 2. d4 exd4 3. Qxd4 Ke7 4. Qe5#
1. g4 e5 2. d4 exd4 3. Qxd4 Ke7 4. Qe5#
 > 1. Nf3/f3 ... 4. Qxd5#
1. Nf3 d5 2. c3 Kd7 3. Qb3 Qe8 4. Qxd5#
1. f3 d5 2. c3 Kd7 3. Qb3 Qe8 4. Qxd5#
 > 1. d3 ... 4. Qb5#
1. d3 d6 2. c4 Kd7 3. Qb3 Kc6 4. Qb5#
 > 1. d4 ... 4. Qg4#
1. d4 f6 2. e4 Kf7 3. Bc4+ Kg6 4. Qg4#
 > 1. e4 ... 4. Qg4# (similar to problem above, same solution as P1254391)
1. e4 f6 2. d4 Kf7 3. Bc4+ Kg6 4. Qg4#
 > 1. f4 ... 4. Qf5#
1. f4 d6 2. e4 Kd7 3. Qh5 Ke6 4. Qf5#
 > 1. g4 ... 4. Bh5#
1. g4 f5 2. Bh3 fxg4 3. Bxg4 g5 4. Bh5#

 > in 4.0 moves:
 > 1. d3 ... 4... d5#/Qf5#
1. d3 e6 2. Kd2 Qf6 3. Ke3 Bc5+ 4. Ke4 d5#
1. d3 e6 2. Kd2 Qf6 3. Ke3 Bc5+ 4. Ke4 Qf5#
 > 1. f3 ... 4... Qf5#
1. f3 e6 2. Kf2 Qf6 3. Ke3 Bc5+ 4. Ke4 Qf5#

 > in 4.5 moves:
 > 1. Nc3 ... 5. c5#
1. Nc3 d5 2. Ne4 Kd7 3. c4 Kc6 4. Qa4+ Kb6 5. c5#
 > 1. Nc3 ... 5. g4#
1. Nc3 e6 2. e3 Ke7 3. Qg4 Kf6 4. Qxg7+ Kf5 5. g4#
 > 1. Nf3 ... 5. Qh3#
1. Nf3 f5 2. d4 Kf7 3. Qd3 Kg6 4. Ne5+ Kh5 5. Qh3#
 > 1. b4/d4 ... 5. Qf6#
1. b4 e5 2. e4 Ke7 3. Qg4 Kd6 4. Qxg7 Ne7 5. Qf6#
1. d4 e5 2. e4 Ke7 3. Qg4 Kd6 4. Qxg7 Ne7 5. Qf6#
 > 1. c3 ... 5. Nh4#
1. c3 f6 2. Nf3 Kf7 3. Qb3+ Kg6 4. Qd5 Nh6 5. Nh4#
 > 1. c4 ... 5. Qb4#
1. c4 d5 2. e3 Kd7 3. Qg4+ Kc6 4. cxd5+ Kb6 5. Qb4#
 > 1. d3 ... 5. f5#
1. d3 e5 2. e4 Ke7 3. Bg5+ Ke6 4. f4 Bd6 5. f5#
 > 1. d3/d4 ... 5. Qxe8#
1. d3 f6 2. e4 Kf7 3. Qg4 Qe8 4. Qxd7 Kg6 5. Qxe8#
1. d4 f6 2. e4 Kf7 3. Qg4 Qe8 4. Qxd7 Kg6 5. Qxe8#
 > 1. d4 ... 5. Bf3#
1. d4 f6 2. g3 Kf7 3. Bg2 Kg6 4. Qd3+ Kh5 5. Bf3#
 > 1. e3 ... 5. Qh3#
1. e3 f6 2. f4 Kf7 3. Qf3 Kg6 4. Bd3+ Kh6 5. Qh3#
 > 1. e4 ... 5. Bc3#
1. e4 d6 2. d3 Kd7 3. Bd2 Ke6 4. Qg4+ Ke5 5. Bc3#
 > 1. f4 ... 5. Qh4#
1. f4 f6 2. c3 Kf7 3. Qa4 Kg6 4. f5+ Kh6 5. Qh4#
 > 1. g4 ... 5. Bh3#
1. g4 f5 2. e4 fxg4 3. Qxg4 Kf7 4. Qf4+ Ke6 5. Bh3#
 > 1. g4 ... 5. Qh3#
1. g4 f5 2. d4 Kf7 3. Qd3 Kg6 4. gxf5+ Kh5 5. Qh3#
 > 1. g4 ... 5. Qh4#
1. g4 f5 2. c3 Kf7 3. Qa4 Kg6 4. gxf5+ Kh6 5. Qh4#

As you can see, sometimes the first move isn't actively part of the 
solution and its only purpose is to prevent a totally different solution 
from working.

     François